Sadao Asakuma

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The present study was carried out to establish porcine defined IVP. In Experiments 1 and 2, we investigated the efficacy of additional 0.6 mM cystine and/or 100 microM cysteamine (Cys) to a defined TCM199 maturation medium with regard to the intracellular glutathione (GSH) concentration and the developmental competence of in vitro matured porcine oocytes(More)
The effects of loop diuretics on the endocochlear direct current (DC) potential and the effective electrical resistance of the cochlear partition were studied. The effective electrical resistance was increased, and the endocohlear DC potential was decreased. The decrease in the endocohlear DC potential must not be caused by breaks in the electrical(More)
The magnitudes of the endocochlear dc potential (EP) during adequate ventilation and during five minutes of anoxia were recorded in control guinea pigs and guinea pigs administered various dosages of kanamycin sulfate. The magnitudes of the EP after five minutes of anoxia were -44.6 +/- 5.9 mV in the controls and +26.6 +/- 9.9 mV in the guinea pigs that(More)
Chloramphenicol is not ototoxic if administered for systemic effect, but topical applications of it to the middle ear produce severe cochlear toxic effects. Ethacrynic acid potentiates the ototoxicity of aminoglycosides. Guinea pigs were administered chloramphenicol or kanamycin sulfate with ethacrynic acid to compare the ototoxicity of chloramphenicol and(More)
The relationship between the calculated value of the effective electrical resistance of the cochlear partition and the distance between the electrode for measuring the EP and the stimulating electrodes has been studied. The calculated value of the effective electrical resistance of the cochlear partition declines linearly with increasing distance between(More)
Gastric acid secretion basally and in response to intragastric meat extract instillation or to tetragastrin, and circulating gastrin concentration basally and after meat extract stimulation were studied in 67 patients with gastroduodenal ulcer, 30 patients after highly selective vagotomy or selective vagotomy for duodenal ulcer, 12 patients after antrectomy(More)
20 mg/kg of body weight of nitrogen mustard-N-oxide hydrochloride ( NMNO ) causes a transient decrease in the magnitude of the endocochlear d.c. potential (EP) in the same manner as does nitrogen mustard (NM). NMNO does not, however, change the electrical resistance of the cochlear partition. When the administered dose of NMNO is increased to 40, 60 and 80(More)
The electrophysiologic and histopathologic changes in the inner ear caused by the administration of cis-diamminedichloroplatinum (CP) were studied in guinea pigs. The endocochlear dc potential (EP) gradually decreased after the intravenous injection of CP and reached approximately 0 mV on the fourth day, but the EP did not become negative. The cochlear(More)